反应详情

317 g of the product of Example 15a were introduced, and a mixture of 250 ml of 100% strength by weight nitric acid and 350 ml of concentrated sulphuric acid were added dropwise, with stirring. The mixture was stirred for 2 hours at 55° C. The batch was then allowed to cool and poured into ice-water. The product was extracted using methylene chloride, and the methylene chloride phase was washed until neutral using sodium hydrogencarbonate solution, dried and freed from readily volatile components on a rotary evaporator. The yield was 339 g (=94% of theory), and the melting point was 101° to 103° C.

1. additionwere added dropwise
2. stirringThe mixture was stirred for 2 hours at 55° C
3. temperatureto cool
4. extractionThe product was extracted
5. washthe methylene chloride phase was washed
6. customdried
7. customfreed from readily volatile components on a rotary evaporator